Hence their "official" generic fantasy world, Yyrth, was a fairly late development, and never had the detail or support of a Forgotten Realms, Greyhawk or Krynn. They tried so hard not to paint anyone into a corner that people are largely on their own in defining the character and direction of games. To a certain extent that is unavoidable, because the more they specialize in any one style or genre the less suited the resulting rules are for others.

Basically, they do not produce many modules, and almost no full scale campaigns, because they want to preserve the GMs ability to design his own. In terms of a business model, however, far more people want to read a book or watch a film than want to write either. That has always been the problem with GURPS; it is simple for PLAYERS, once familiar with the rules, because they can jump into the middle of any setting from Star Wars to Cthulhu to Supers to High Fantasy and continue using the same 3d6 vs. DX/IQ system they know so well. For GMs it almost always represents a TREMENDOUS amount of work because, while the mechanics allow almost anything, almost nothing is prefab.

GURPS is more concerned with rigorous realistic rules than actual games, and the desire to retain its characteristic generic flexibility works against developing a lot of setting specific modules and campaigns. Look at the single player and group modules at the end of the 3rd ed. Basic Set book; you could drop either into any pre-industrial setting you like. Magic is optional in both (in fact, you can destroy All in a Nights Work pretty thoroughly with a couple basic spells like sleep) and the single player one even shows how to run it as a post-apocalyptic dystopian adventure a la Mad Max (Max the Guard becomes significantly more lethal with a shotgun rather than a sword.)

GURPS has gotten better over the years, publishing a few player and GM guides with character templates and the like, but not much. They could do a better job publishing modules and campaigns rather than just tossing a few "adventure seeds" into each world book or supplement, but I do not expect it. Their target audience is people who want to design their own games tailored to a setting they already have in mind, and in the case of people who want to play in existing settings they still expect people to know what kind of campaign they want to run there, so they avoid providing any. Hence my GURPS: The Prisoner worldbook has stats on Rover and a few adventure seeds (The Village as Hogans Heroes is appealing... ) but the only module or campaign is a basic recap of "Arrival" for PCs.

In many ways, GURPS lends itself better to the online era of RPGs than d20; making the GM obsolete by dropping all the ajudication in a computer lap provides desperately needed streamlining. The problem is that PCs becoming more ubiquitous has increased the size of the RPG community without increasing the number of role players. Just the basic terms "gamer" and "RPG" have VERY different connotations than they did 20 years ago; this thread was not the first time I saw someone compare AD&D 4th ed. to console gaming. As much as hard core role players and realism junkies dislike it, the percentage of "gamers" who prefer action packed cinematic campaigns has probably gone up rather than down with the rise of computers, and the premium computers place on video and audio rather than imagination only encourages that.